1. Field of the Invention
This invention relates to a process for inhibiting tumor development through the use of a Brucella abortus preparation, and, more specifically, relates to the use of a specific nonviable, aqueous, ether-extracted Brucella abortus preparation (BRU-PEL) which is introduced into the patient in a dosage effective to resist tumor development.
2. Description of the Prior Art
As a result of the great medical need to develop effective antitumor preparations, a large number of substances, both synthetic and of biological origin, have been investigated as immunomodulators in the treatment of tumors. Recently a great deal of work has centered around the use of living attenuated BCG (Bacillus Calmette-Guerin) organisms or killed cells of Corynebacterium parvum as biologically derived immunomodulators. With respect to the BCG organisms, there remains the risk of the patient's contracting tuberculosis as the organisms are live.
The beneficial use of Brucella abortus against tumors in mice has previously been known. See Z. Hirnle, "The Effect of Brucella Abortus Infection on Transmissible Crockers Sarcoma in Mice", Acta Medica Polona, pages 219-241 (1960), and Japanese Patent 17,150 (1971). This latter reference claims that a polysaccharide fraction obtained from heat-killed cells of Brucella abortus is capable of inhibiting growth of Sarcoma-180 in mice.
There remains a need for an improved antitumor agent which is less toxic, more stable and produces more uniform results than those previously known.